1. Field of the Invention
This disclosure relates to a portable device for delivering light to the blood supply of a human body to treat jaundice, excessive bilirubin, mood disorders, sleep and body cycle problems in humans. More particularly, the present disclosure concerns a portable planar light delivery pad, and methods related thereto, for delivering light to the blood supply by exposing a non-ocular portion of the body to light at pre-selected wavelengths and intensity, particularly for the treatment of excessive bilirubin in infants and others.
2. The Related Art
Bilirubin is the waste product that results from the breakdown of hemoglobin molecules from worn out red blood cells. Ordinarily, it is excreted from the body as the chief component of bile. Excessive levels of bilirubin stain the tissues in the skin yellow, resulting in what is called jaundice. Very high levels of bilirubin in the bloodstream can cause permanent damage to certain areas of the brain of newborn infants, referred to as kernicterus. This can cause a characteristic form of crippling known as athetoid cerebral palsy. To prevent this from happening, bilirubin levels are closely monitored in newborns. Excessive levels of bilirubin are treated by either phototherapy (xe2x80x9cbilirubin lightsxe2x80x9d) or exchange transfusion.
Regarding phototherapy, other problems and disorders have been found to respond to the application of light to non-ocular areas of the body. These include seasonal affective disorder, mood disorders and sleep-related disorders, such as the disorientation of the human circadian cycle that often results from traveling through various time zones, commonly referred to as xe2x80x9cjet lag.xe2x80x9d
In light therapy, it has also been determined that some wavelengths of light are more effective in treating certain disorders than others. Thus, treatment using light with a single wavelength or a plurality of wavelengths within a fairly narrow range is often used. Blue light has been found to most effective in breaking down bilirubin, referred to as neonatal phototherapy. In addition, it may be desirable, wherever possible to treat the infant or other patient as an out-patient, rather than admitting them to the hospital.
Phototherapy has traditionally been conducted using fluorescent blue light therapies or blue fiberoptic therapies. One problem with fluorescent blue light therapy is that it may provide additional light in a broader bandwidth than necessary. In addition, fluorescent light banks or boxes emit a substantial amount of heat causing substantial discomfort and possibly even danger to newborn infants. Light banks or boxes are not portable, requiring the baby to remain in one location. The mother or other attendants are not able to care for it during fluorescent phototherapy. In addition, the light is directed to the entire body, including the eyes, requiring eye shields or shades to be used. Consequently, light banks or boxes are not as conducive to use by outpatients at home.
Fiberoptic therapy is slightly more conducive for out-patient use, since the light generator and fiber-optic system are small enough to bring to a patient""s home. One difficulty with blue fiberoptic therapy is that the light generation source and light delivery system may be complicated and expensive. Fiberoptic lamp units also produce excessive heat that can be troublesome. The lamp required for generating light for a delivery system has a relatively short life (200-300 hours), is expensive and therefore complicates the delivery of light to an outpatient.
U.S. Pat. No. 6,135,117 (Campbell et al.) discloses a method for providing non-ocular light to the body using a large fiber-optic light pad to treat jaundice in newborns. The system is described as being useful for treating circadian rhythm problems and various sleep disorders. The pad is attached to a bulky high-intensity light supply and requires a large delivery line running from the light supply to the pad. Campbell also indicates that the delivery of extra-ocular light stimulus to the body can mediate and shift the phase of a circadian cycle. However, the Campbell system is encumbered by the above-mentioned disadvantages with respect to fiber-optic systems.
Regarding exchange transfusion, this approach is an expensive, difficult and somewhat dangerous process, since blood from external sources is being introduced to the body. The process is also invasive and cumbersome, requiring the patient to remain at the same location and substantially immobile during the exchange process. Consequently, it is of very limited usefulness, although it can be invaluable in a crisis.
Some systems have been developed to deliver light to the vascular tissues using light emitting diodes (LEDs). U.S. Pat. No. 6,290,713 (Russell) discloses an apparatus for providing light from LEDs to infants and others to treat light-related illnesses. A flexible substrate has LEDs mounted on the substrate to direct light to the patient. However, a cover is placed over the LEDs with light diffusers thereon, such as glass bubbles or reflectors. The diffusers are meant to distribute light more evenly. However, they cause a substantial attenuation in the amount of light directed to the patient, so that more power must be applied to the LEDs to attain the amount of light needed. As a result, extensive cooling systems are required for the Russell device to conduct away excessive heat. These problems make the Russell device relatively complicated and expensive to produce and use.
More recent research has been directed to the possible use of LEDs as light delivery elements for providing light therapy. A recent article by Vreman, Wong and Stevenson broadly discussed the possible future use of surface mount LEDs mounted on rigid or flexible low voltage circuit boards to form devices such as canopies, pads, blankets and even clothing. See Vreman et al, xe2x80x9cLight Emitting Diodes For Phototherapy For the Control of Jaundice,xe2x80x9d Biologic Effects of Light 2001, p. 355, Kluwer Academic Publishers (Symposium June 2001). However, the Vreman article described the use of surface mounted LEDs, which would be likely to encounter difficulties similar to those of the Russell device.
Accordingly, there exists a need for a light delivery system that provides light to a patient simply and effectively, with a minimum of heat and complicated apparatus. A further need exists to be able to apply monochromatic light to eliminate unnecessary light and heat. Yet another need exists to provide a light delivery system that is light-weight, flexible and uniform in the application of light to the body. Another possible need exists for a light delivery device to allow handling and treatment of the patient by caregivers during therapy. Additionally, a light-delivery source is needed that has long life and requires little maintenance. A yet further need exists for a light delivery system that can control the amount of power directed to the light source, to minimize the amount of heat to which the patient is exposed, and to time the exposures according to the specific needs of each patient. Another need exists to have a light-therapy system that is able to treat a variety of problems, including jaundice, excess bilirubin, seasonal affective disorders, sleep-related disorders and mood disorders.
The present disclosure involves providing light to areas of the body where there are substantial blood vessels near the surface of the skin, the vascular tissue regions, so that the light can interact with photoactive substances in the blood to correct various problems. Several effective areas for the administration of light have been found, such as the popliteal region, the area directly behind the knee joint, as well as the chest, neck, arm and abdominal area. In treating jaundice for newborn infants, the abdominal area has been found to be most advantageous because of ease in access, extensive vascular tissue close to the skin and because the delivery unit can be blanket shaped to be comfortable and cover a relatively large area. The use of LEDs makes the device light-weight, inexpensive, low in heat output and able to deliver different wavelengths of light as needed. LEDs also provide a light delivery source that has a long life of several years and requires little or no maintenance.
The structure of the portable light delivery apparatus enables the LEDs to be mounted in a through-hole arrangement to provide maximum bright exposure with a minimum amount of heat. A controller enables the intensity of the light to be varied, and switching apparatus enables the light to be administered in duty cycles, maximizing the light penetration while maintaining the heat at tolerable levels. Some or all of the controller circuitry may be remote from the patient, lessening exposure to heat. A programmable device may be included as part of the controller for timing and sequencing the application of light, thereby customizing the phototherapy to accommodate each patient""s needs.
In one implementation of the portable light delivery apparatus, a portable light-emitting device is provided for delivering light to the blood supply of a human body of a subject through a non-ocular area of skin on the body. A light delivery unit having multiple spaced-apart apertures therein is disposed for positioning on a portion of the body. A plurality of individual light sources are each disposed within one of the apertures of the light delivery unit for directing light toward the body. A power supply is connected to the light delivery unit for delivering power to the light sources. A controller unit is disposed between the power supply and the light delivery unit for controlling the delivery of power to the light sources.
In another implementation, a light-emitting device is provided for delivering light to the blood supply of a human body of a subject through a non-ocular area of skin on the body. A flexible unit is provided for positioning on a portion of the body having a plurality of spaced apart apertures therein. A plurality of light emitting diodes (LEDs) are each disposed on the flexible unit to extend through one of the apertures to direct light to the body. A power supply is connected to the LEDs for delivering power thereto.
In a further implementation, a method is provided using a portable light-emitting device to deliver light to the blood supply of a human body of a subject through a non-ocular area of skin on the body. A light delivery unit having multiple spaced-apart apertures therein is positioned on a portion of the body. Light is directed to a portion of the body from a plurality of individual light sources, each being disposed within one of the apertures of the light delivery unit. Power is provided to the light sources from a power supply connected to the light delivery unit. The delivery of power to the light sources is controlled with a controller unit disposed between the power supply and the light delivery unit.
In yet another implementation, a method is provided of using a light-emitting device to deliver light to the blood supply of a human body of a subject through a non-ocular area of skin on the body. A flexible unit having a plurality of spaced apart apertures therein is positioned on a portion of the body. A plurality of light emitting diodes (LEDs) are disposed on the flexible unit, each LED extending through one of the apertures to direct light to the body. Power is provided to the LEDs from a power supply connected to the LEDs for delivering power thereto.
The foregoing apparatus and methods may be used to effectively treat an infant for jaundice, to treat any subject for an excess of bilirubin or to provide photo-therapy for a number of illnesses and disorders, including seasonal affective disorders, sleep-related disorders and mood disorders.